dom_position.cpp

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                if (textOffset >= box->start() && textOffset <= box->end())
                    return it.current();
                else if (box != textRenderer->lastTextBox() && 
                         !box->nextOnLine() && 
                         textOffset == box->start() + box->len())
                    return it.current();
            }
        }
    }
    
    return lastVisible.isNotNull() ? lastVisible : *this;
}

Position Position::equivalentRangeCompliantPosition() const
{
    if (isNull())
        return Position();

    // Make sure that 0 <= constrainedOffset <= num kids, otherwise using this Position
    // in DOM calls can result in exceptions.
    long maxOffset = node()->isTextNode() ? static_cast<TextImpl *>(node())->length(): node()->childNodeCount();
    long constrainedOffset = offset() <= 0 ? 0 : kMin(maxOffset, offset());

    if (!node()->parentNode())
        return Position(node(), constrainedOffset);

    RenderObject *renderer = node()->renderer();
    if (!renderer)
        return Position(node(), constrainedOffset);
        
    if (!renderer->isReplaced() && !renderer->isBR())
        return Position(node(), constrainedOffset);
    
    long o = offset();
    const NodeImpl *n = node();
    while ((n = n->previousSibling()))
        o++;
    
    // Make sure that 0 <= constrainedOffset <= num kids, as above.
    NodeImpl *parent = node()->parentNode();
    maxOffset = parent->isTextNode() ? static_cast<TextImpl *>(parent)->length(): parent->childNodeCount();
    constrainedOffset = o <= 0 ? 0 : kMin(maxOffset, o);
    return Position(parent, constrainedOffset);
}

Position Position::equivalentDeepPosition() const
{
    if (isNull() || node()->isAtomicNode())
        return *this;

    NodeImpl *child = 0;
    Position pos(*this);
    if (offset() >= (int)node()->childNodeCount()) {
        child = node()->lastChild();
        pos = Position(child, child->caretMaxOffset());
        ASSERT(child);
        while (!child->isAtomicNode() && pos.node()->hasChildNodes()) {
            child = pos.node()->lastChild();
            ASSERT(child);
            pos = Position(child, child->caretMaxOffset());
        }
    }
    else {
        child = node()->childNode(offset());
        ASSERT(child);
        pos = Position(child, 0);
        while (!child->isAtomicNode() && pos.node()->hasChildNodes()) {
            child = pos.node()->firstChild();
            ASSERT(child);
            pos = Position(child, 0);
        }
    }
    return pos;
}

bool Position::inRenderedContent() const
{
    if (isNull())
        return false;
        
    RenderObject *renderer = node()->renderer();
    if (!renderer)
        return false;
    
    if (renderer->style()->visibility() != VISIBLE)
        return false;

    // FIXME: This check returns false for a <br> at the end of a line!
    if (renderer->isBR() && static_cast<RenderText *>(renderer)->firstTextBox()) {
        return offset() == 0;
    }
    else if (renderer->isText()) {
        RenderText *textRenderer = static_cast<RenderText *>(renderer);
        for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
            if (offset() >= box->m_start && offset() <= box->m_start + box->m_len) {
                return true;
            }
            else if (offset() < box->m_start) {
                // The offset we're looking for is before this node
                // this means the offset must be in content that is
                // not rendered. Return false.
                return false;
            }
        }
    }
    else if (offset() >= renderer->caretMinOffset() && offset() <= renderer->caretMaxOffset()) {
        // return true for replaced elements, for inline flows if they have a line box
        // and for blocks if they are empty
        if (renderer->isReplaced() ||
            (renderer->isInlineFlow() && static_cast<RenderFlow *>(renderer)->firstLineBox()) ||
            (renderer->isBlockFlow() && !renderer->firstChild() && renderer->height()))
            return true;
    }
    
    return false;
}

bool Position::inRenderedText() const
{
    if (isNull() || !node()->isTextNode())
        return false;
        
    RenderObject *renderer = node()->renderer();
    if (!renderer)
        return false;
    
    RenderText *textRenderer = static_cast<RenderText *>(renderer);
    for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
        if (offset() < box->m_start) {
            // The offset we're looking for is before this node
            // this means the offset must be in content that is
            // not rendered. Return false.
            return false;
        }
        if (offset() >= box->m_start && offset() <= box->m_start + box->m_len)
            return true;
    }
    
    return false;
}

bool Position::isRenderedCharacter() const
{
    if (isNull() || !node()->isTextNode())
        return false;
        
    RenderObject *renderer = node()->renderer();
    if (!renderer)
        return false;
    
    RenderText *textRenderer = static_cast<RenderText *>(renderer);
    for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
        if (offset() < box->m_start) {
            // The offset we're looking for is before this node
            // this means the offset must be in content that is
            // not rendered. Return false.
            return false;
        }
        if (offset() >= box->m_start && offset() < box->m_start + box->m_len)
            return true;
    }
    
    return false;
}

bool Position::rendersInDifferentPosition(const Position &pos) const
{
    if (isNull() || pos.isNull())
        return false;

    RenderObject *renderer = node()->renderer();
    if (!renderer)
        return false;
    
    RenderObject *posRenderer = pos.node()->renderer();
    if (!posRenderer)
        return false;

    if (renderer->style()->visibility() != VISIBLE ||
        posRenderer->style()->visibility() != VISIBLE)
        return false;
    
    if (node() == pos.node()) {
        if (node()->id() == ID_BR)
            return false;

        if (offset() == pos.offset())
            return false;
            
        if (!node()->isTextNode() && !pos.node()->isTextNode()) {
            if (offset() != pos.offset())
                return true;
        }
    }
    
    if (node()->id() == ID_BR && pos.inRenderedContent())
        return true;
                
    if (pos.node()->id() == ID_BR && inRenderedContent())
        return true;
                
    if (node()->enclosingBlockFlowElement() != pos.node()->enclosingBlockFlowElement())
        return true;

    if (node()->isTextNode() && !inRenderedText())
        return false;

    if (pos.node()->isTextNode() && !pos.inRenderedText())
        return false;

    long thisRenderedOffset = renderedOffset();
    long posRenderedOffset = pos.renderedOffset();

    if (renderer == posRenderer && thisRenderedOffset == posRenderedOffset)
        return false;

    LOG(Editing, "renderer:               %p [%p]\n", renderer, renderer ? renderer->inlineBox(offset()) : 0);
    LOG(Editing, "thisRenderedOffset:         %d\n", thisRenderedOffset);
    LOG(Editing, "posRenderer:            %p [%p]\n", posRenderer, posRenderer ? posRenderer->inlineBox(offset()) : 0);
    LOG(Editing, "posRenderedOffset:      %d\n", posRenderedOffset);
    LOG(Editing, "node min/max:           %d:%d\n", node()->caretMinOffset(), node()->caretMaxRenderedOffset());
    LOG(Editing, "pos node min/max:       %d:%d\n", pos.node()->caretMinOffset(), pos.node()->caretMaxRenderedOffset());
    LOG(Editing, "----------------------------------------------------------------------\n");

    InlineBox *b1 = renderer ? renderer->inlineBox(offset()) : 0;
    InlineBox *b2 = posRenderer ? posRenderer->inlineBox(pos.offset()) : 0;

    if (!b1 || !b2) {
        return false;
    }

    if (b1->root() != b2->root()) {
        return true;
    }

    if (nextRenderedEditable(node()) == pos.node() && 
        thisRenderedOffset == (long)node()->caretMaxRenderedOffset() && posRenderedOffset == 0) {
        return false;
    }
    
    if (previousRenderedEditable(node()) == pos.node() && 
        thisRenderedOffset == 0 && posRenderedOffset == (long)pos.node()->caretMaxRenderedOffset()) {
        return false;
    }

    return true;
}

Position Position::leadingWhitespacePosition(EAffinity affinity, bool considerNonCollapsibleWhitespace) const
{
    if (isNull())
        return Position();
    
    if (upstream(StayInBlock).node()->id() == ID_BR)
        return Position();

    Position prev = previousCharacterPosition(affinity);
    if (prev != *this && prev.node()->inSameContainingBlockFlowElement(node()) && prev.node()->isTextNode()) {
        DOMString string = static_cast<TextImpl *>(prev.node())->data();
        const QChar &c = string[prev.offset()];
        if (considerNonCollapsibleWhitespace ? (c.isSpace() || c.unicode() == 0xa0) : isCollapsibleWhitespace(c))
            return prev;
    }

    return Position();
}

Position Position::trailingWhitespacePosition(EAffinity affinity, bool considerNonCollapsibleWhitespace) const
{
    if (isNull())
        return Position();

    if (node()->isTextNode()) {
        TextImpl *textNode = static_cast<TextImpl *>(node());
        if (offset() < (long)textNode->length()) {
            DOMString string = static_cast<TextImpl *>(node())->data();
            const QChar &c = string[offset()];
            if (considerNonCollapsibleWhitespace ? (c.isSpace() || c.unicode() == 0xa0) : isCollapsibleWhitespace(c))
                return *this;
            return Position();
        }
    }

    if (downstream(StayInBlock).node()->id() == ID_BR)
        return Position();

    Position next = nextCharacterPosition(affinity);
    if (next != *this && next.node()->inSameContainingBlockFlowElement(node()) && next.node()->isTextNode()) {
        DOMString string = static_cast<TextImpl *>(next.node())->data();
        const QChar &c = string[0];
        if (considerNonCollapsibleWhitespace ? (c.isSpace() || c.unicode() == 0xa0) : isCollapsibleWhitespace(c))
            return next;
    }

    return Position();
}

void Position::debugPosition(const char *msg) const
{
#if !NOKIA_CHANGES
    if (isNull())
        fprintf(stderr, "Position [%s]: null\n", msg);
    else
        fprintf(stderr, "Position [%s]: %s [%p] at %d\n", msg, node()->nodeName().string().latin1(), node(), offset());
#endif
}

#ifndef NDEBUG
#define FormatBufferSize 1024
void Position::formatForDebugger(char *buffer, unsigned length) const
{
    DOMString result;
    DOMString s;
    
    if (isNull()) {
        result = "<null>";
    }
    else {
        char s[FormatBufferSize];
        result += "offset ";
        result += QString::number(m_offset);
        result += " of ";
        m_node->formatForDebugger(s, FormatBufferSize);
        result += s;
    }
          
    strncpy(buffer, result.string().latin1(), length - 1);
}
#undef FormatBufferSize
#endif


Position startPosition(const Range &r)
{
    if (r.isNull() || r.isDetached())
        return Position();
    return Position(r.startContainer().handle(), r.startOffset());
}

Position startPosition(const RangeImpl *r)
{
    if (!r || r->isDetached())
        return Position();
    int exceptionCode;
    return Position(r->startContainer(exceptionCode), r->startOffset(exceptionCode));
}

Position endPosition(const Range &r)
{
    if (r.isNull() || r.isDetached())
        return Position();
    return Position(r.endContainer().handle(), r.endOffset());
}

Position endPosition(const RangeImpl *r)
{
    if (!r || r->isDetached())
        return Position();
    int exceptionCode;
    return Position(r->endContainer(exceptionCode), r->endOffset(exceptionCode));
}

} // namespace DOM